In the new Galactic Challenge, I completed the Tier X several times with different teams, but the feat isn't being validated. However, it did work for the first two tiers when I used my 3-stars ...
Ideas
EA_Gunner
EA QV Team
EA QV TeamStudio released a server fix yesterday to address an issue related to mods. They believe the server issues we saw during the week are also causing this issue. Can you try to play another battle and check if the feats are awarded now?